Closed beam with expanded metal sections

ABSTRACT

An elongate beam that is constructed of a sheet metal having expanded metal sections. The beam has a closed profile that has at least two side sections made with the expanded metal. The opposite side edges of the sheet metal are attached to one another so that the sheet metal forms a closed beam structure.

The present invention relates to a beam with a fully and/or partiallyclosed profile exhibiting at least two sides.

BACKGROUND INFORMATION AND SUMMARY OF THE INVENTION

A considerable need exists in many technical areas for beams of lowweight, high strength with regard to both resistance to bending andresistance to compression, and advantageous collapse characteristics.Such beams are desirable in the vehicle industry, the constructionindustry, the road equipment industry etc., and especially the passengercar industry, since an advantageous weight-to-strength ratio permitslower fuel consumption and advantageous collapse characteristics or aconsiderable capacity to absorb high energy in the course of deformationto a state in which the beam may be regarded as having collapsed. Thislatter characteristic is desirable in so-called impact protection zonesin passenger cars, buses and lorries or similar vehicles.

The basis of the present invention is the problem of satisfying theaforementioned requirements.

This problem is solved in accordance with the present invention by thebeam referred to by way of introduction, in that the beam is profiledfrom a coiled sheet metal strip which exhibits an elongated section ofexpanded metal along at least one side of the finished profile, in thatthe sections of the sheet metal strip connecting the sides are unbroken,and in that both meeting edges of the sheet metal strip are connected orattached to one another to form the closed profile. All the sidesexhibit one or more sections of expanded metal. The sections connectingthe sides are unbroken. The sides are connected or attached to oneanother to form the closed profile. Two of the sides are connected toone another by folding the unbroken edge sections. Two of the sides areconnected to one another by welding. When the beam has a multi-sidedclosed profile, it is advantageous for the corner sections to beunbroken and for the fold or connection closing the profile to besituated at one of the corners in the unbroken edge sections. The beamis profiled from a sheet metal strip which exhibits an elongated sectionof expanded metal on each side of the finished profile and an elongatedsection of sheet metal strip at each corner.

A beam in accordance with the present invention provides unimaginedopportunities within many technical areas, where components can be madeappreciably lighter without in any way having to jeopardize the strengthof the component in question. Appreciably improved energy-absorbingcharacteristics are also offered, since appreciably greater energy isconsumed or required to bring about the complete collapse of a beam inaccordance with the present invention than in the case of conventionalbeam structures. A beam in accordance with the present invention alsopermits economies of both space and weight, which in turn lead toappreciably better operating economy. A beam in accordance with thepresent invention also permits the use of simpler and more efficientinstallation and assembly methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational front view of a preferred embodiment of thebeam of the present invention;

FIG. 2 is an elevational rear view of the embodiment shown in FIG. 1;

FIG. 3 is a cross-sectional view of the present invention;

FIG. 4 is a detailed view of the present invention; and

FIG. 5 is a schematic view of the manufacturing process to make the beamof the present invention.

DETAILED DESCRIPTION

The present invention is described below in greater detail withreference to the accompanying drawings. FIG. 1 shows a view from theside of an embodiment of a beam in accordance with the presentinvention. FIG. 2 shows a view from another side of the beam in FIG. 1.FIG. 3 shows a cross-section through the beam in FIGS. 1 and 2 toillustrate its quadrangular profile. FIG. 4 shows on a large scale apart of a section of strip metal in the beam in accordance with theprevious Figures. FIG. 5 shows a line for the manufacture of beams inaccordance with the invention.

The embodiment of a beam in accordance with the present invention shownin the drawings may, in principle, be of infinite length and of anydesired profile, although it is shown in FIG. 3 to have a quadrilateraland essentially square profile. A beam in accordance with the presentinvention may, as stated, exhibit any suitable profile, for example atwo-sided oval profile or elliptical profile, a quadrilateral profile ora quadrangular profile in accordance with the drawings, a three-sidedprofile and many variants and combinations of such profiles. It isconceivable, for example, to have a profile which consists in principleof a number of triangular profiles, for example three triangularprofiles or even four triangular profiles, which are attached orconnected to one another in an appropriate fashion, for example withtheir tips meeting one another. Quadrangular profiles need not besquare, of course, but may exhibit in principle any quadrangular form.The angles in the quadrilateral profiles also need not be 90°, but maybe angles other than right-angles.

The beam illustrated in the drawings is quadrilateral, as alreadymentioned above, and has a section 1 of expanded metal on each of thethree sides and a section 2 of expanded metal on the fourth side. Thefourth side also exhibits a folded section 3 of essentially conventionaltype. The profile exhibits unbroken sections between the sides. Thefolded section 3 engages in an essentially conventional fashion in thetwo meeting, unbroken edge sections that are obtained after profiling ofthe beam to the quadrangular form shown.

The folded section 3 may be replaced by some other form of connection orfolding. The connection may well consist of a weld in the form of a spotweld or a seam weld. The choice of connection or attachment dependslargely on the choice of material used for the metal strip.

FIG. 4 illustrates a part of the sections 1, 2 of expanded metal indetail, and it can be appreciated from this detailed Figure that thesections of expanded metal have a conventional form with a number ofholes between bridges or connections 5 in the sheet metal itself.

It is also possible, of course, to have other types of expanded metalstructures, although the type illustrated is the preferred type. It mustbe pointed out in this respect that the upward-facing curves in thebridges 5 are displaced up and out of the plane of the drawing, whereasthe downward-facing curves of the bridges 5 are displaced inwards andinto the plane of the drawing, although they are connected to oneanother in such a way that the upward-facing curve is connected to thedownward-facing curve.

It must also be pointed out that it is naturally not necessary for thebeam to exhibit sections of expanded metal on all sides, but that it maybe appropriate in certain cases to have expanded metal on one or twosides, for example two opposing sides, or on two or three adjacent sidesof a quadrangular beam. It is also conceivable to have an oval beam, inwhich one side exhibits a section of expanded metal, whereas the otherside is unbroken. The unbroken edge sections may be provided withsections of expanded metal or holes intended to lighten the structure.

The sheet metal from which a beam in accordance with the presentinvention is manufactured may consist of many different materials, forexample aluminium, or steel etc.

A beam in accordance with the present invention can be manufactured inan expander, which makes it possible to achieve sections of expandedmetal that are separated by unbroken sections of sheet metal, inconjunction with which a profiling machine and a folding machine or awelding machine are positioned directly after the expander in question.The profiling machine and the folding machine or the welding machine maybe separate machines from the expander.

A beam in accordance with the present invention will exhibitsufficiently good strength characteristics, and may be manufactured atsuch low cost that it will be capable of being used within theconstruction industry as a load-bearing structural beam, where it canreplace the wooden beams of both small and large dimensions used today.

BUSINESS IDEA

Self-contained profiles of expanded metal and unperforated plate aremanufactured from a coil of sheet metal strip. Expanded metal profileswith edges and/or strips of unperforated plate are roller-formed. Theinvention allows manufacturing of a large quantity of products.

APPLICATIONS

pillars and beams for building constructions

containers and buildings in steel and aluminium, for example buildingplatform accommodation

energy-absorbing supporting structures for road equipment, for examplelight columns

furniture frames

tubular structures

cable support system and protection (shielding), refining elements anddiffusers, etc.

insulation of tunnels for noise absorption

impact safety in the design of motor vehicles

rib frames, for example in lightweight boats

PROPERTIES

low weight

low energy transmission (noise and heat)

high energy absorption by deformation

low-cost, rapid production in large quantities

simple perforation and jointing, etc.

flexibility of design and product qualities

GENERAL

Machine investment cost depends on the thickness of the metal strip, thewidth of the metal strip and the post-production equipment

A rotary expander has high production capacity

Each unit can be produced at a lower cost compared to a profile madefrom untreated metal strip of the same plate thickness

Processing and material savings give the product a surplus

The invention offers wide scope for giving each product the specificqualities demanded, and

The technique is today best suitable for metal strip of up to 3-5 mm inthickness.

MANUFACTURING PROCESS

The aforementioned profiles can be manufactured in a straight line froma coil of sheet metal strip. A production line can consist of a rotaryexpander, a roller-former and, for example, a high-frequency (HF)welding machine or an edge folder followed by a cross-cutting machine.Sections of the metal strip are expanded in the rotary expander. Areasof unperforated metal are left between the expanded areas. Aself-contained profile, for example round or square, is shaped in theroller-former. The unperforated area forms the edges in corneredprofiles. The profiles are sealed, for example, with a weld or a foldedseam. If a folded seam is chosen, the seam is produced in theroller-forming process. A welded seal is made as in the case of tubemanufacturing, using an HF weld. Other methods of profile sealing can beused.

Many modifications are conceivable, of course, within the scope of theidea of invention defined in the following Patent Claims.

I claim:
 1. A beam having a closed profile, comprising:an elongatemember having a first intermediate side section and a secondintermediate side section that is integrally attached to the firstintermediate side section by a first solid portion, the elongate memberhaving a third intermediate side section that is integrally attached tothe second intermediate side section by a second solid portion, thefirst, second and third intermediate side sections being made of a sheetmetal strip including an expanded metal; and the elongate member havinga first side edge and a second side edge, the first side edge having aninterlocking mechanism and the second side edge having an interlockingmechanism so that the first side edge is interlocked with the secondside edge by the interlocking mechanisms to form a closed profile. 2.The beam according to claim 1 wherein the side edges of the elongatemember are made of a solid material.
 3. The beam according to claim 1wherein the side edges of the elongate member are made of a solidmaterial and the side edges are attached to one another by welding theside edges to each other.
 4. The beam according to claim 1 wherein thebeam is a quadrilateral closed profile and the side edges of theelongate member are attached to one another at a corner of thequadrilateral closed profile.
 5. A method of manufacturing profiles ofexpanded metal comprising the steps of:providing a straight productionline; providing a coiled sheet metal strip having a first side edge anda second opposite side edge, the coiled sheet metal strip having afirst, second and third side section, the first side section beingintegrally attached to the second side section and the third sidesection being integrally attached to the second side section; providinga rotary expander, roll former, and a welding machine disposed on theproduction line; expanding the first, second and third side section ofthe sheet metal strip in the rotary expander; forming the expanded sheetmetal strip into a closed profile in the roll former; and welding thefirst side edge of the sheet metal strip to the second opposite sideedge in the welding machine when the sheet metal strip is in the closedprofile.
 6. The method according to claim 5 wherein the step ofexpanding the sheet metal strip comprises the steps of expandingportions of the sheet metal strip and separating the expanded portionswith solid elongate portions and the step of forming the expanded sheetmetal comprises bending the solid elongate portions of the sheet metalstrip and forming a self-contained profile and sealing theself-contained profile.
 7. The method according to claim 6 wherein thestep of forming the self-contained profile comprises forming a squareshaped profile.
 8. The method according to claim 6 wherein the step ofsealing the self-contained profile comprises welding together edges ofthe self-contained profile.
 9. The method according to claim 6 whereinthe step of sealing the self-contained profile comprises folding a firstedge of the self-contained profile about a second edge of theself-contained profile.
 10. The method according to claim 5 wherein thestep of expanding the sheet metal strip comprises producing a foldedseam in the sheet metal strip.
 11. The method according to claim 5wherein the step of welding comprises the step of providing a highfrequency welding machine and producing a welded seam in the sheet metalstrip.